Campaign, multiplayer, basically all the modes should include the compass from Reach, flashlight and nightvision, and under certain gametype rules I think VISR would be neat. All would be able to be disabled and enabled seperately for game modes. Also, a more indepth weather and skybox diversity? Actually be capable of changing time of day and altering weather conditions to a greater extent would be neat. (This would go hand in hand with a FarCry-like terrain editor with the already great Halo Forge)
Please add your idea to the existing wishlist thread at https://www.halowaypoint.com/en-us/forums/29568daf8cd14083bd1b70a810bf3581/topics/halo-6-wishlist/08b5d0e4-ff65-47a1-b37b-8cfb3cce8987/posts